Polyethylene (PE) and polyvinyl chloride (PVC) are plastics formed through a mechanism called free radical polymerization. Likewise, they are the most commonly used materials in underground pipes and many other items used in daily life. They have several things in common, but there are also obvious differences. What is the difference between them?
PE film, like other plastics, starts from the distillation of hydrocarbon fuels (in this case ethane), called light ends, called "fractions", some of which are combined with other catalysts to produce plastics (usually through polymerization) Or polycondensation reaction). You can learn more about the process here. PE film has sheets, rods, and even various special shapes (LDPE, HDPE, etc.), so it is very suitable for subtraction processing on milling machines or lathes.
First of all, in terms of structure, PVC is formed by connecting a long chain of carbon atoms with chlorine atoms. The PE film is a large chain of carbon atoms, and only hydrogen atoms are connected to it. PVC always has the same basic structure. However, according to the degree of branching of the main chain in each polymer, PE film is divided into several different types. Certain types of polyethylene (such as low density polyethylene) are highly branched, while other types have a less branched structure.
In addition, PE film has strong safety performance, solid form, non-toxic. PE film is usually used in food processing. It may be toxic if inhaled in the form of vapor or liquid and/or absorbed into the skin or eyes (ie during the manufacturing process). Be careful and especially follow the instructions for handling molten polymer. PE film is a very useful commodity plastic, especially in product design companies. Due to the diversity of PE variants, PE film has been widely used. For some projects, other materials that are easier to prototype (such as ABS) can be used to prototype parts that will eventually be mass-produced in PE film.
Both PVC film and PE film are waterproof, but PVC is even more so. Therefore, it is usually used in bottles, doors, windows and safe water pipelines. Because the chlorine atoms released during the combustion process inhibit the combustion process, it is also more fireproof. This material also has good stretch, adhesion and most importantly non-corrosiveness, so it can also be used as a cling film.
Therefore, no matter in cold or high temperature environment, they can preserve and display food well. People have misunderstandings about polyvinyl chloride containing chemicals that are harmful to the human body, but the polyvinyl chloride film used in the Food and Drug Administration (FDA) approved lace products used in food production is completely safe for food packaging.
As for PE film, PE film is also widely used in daily necessities, such as baby bottles, shopping bags and even bulletproof vests. PE film has no plasticizer, so it is safe for food packaging. But because of this, the elasticity of PE film is not as good as that of PVC, and it is not as sticky. Therefore, most commercial kitchens use PVC film instead of PE film.
Because PE film is softer, more malleable and flexible than PVC, it is most commonly used in gas pipelines. The main purpose of the PE film pipe is that the hot melt joint can form a continuous pipe, making it stronger than before and minimizing leakage!